Catalytic System for CO2/Epoxide Copolymerization

ABSTRACT

The present invention relates to a method of manufacturing a polycarbonate including the process of copolymerizing epoxide compound and CO2 using cobalt(III) or chromium(III), where the ligands contains at least 3 ammonium cations, central metal has formal −1 charge, and conjugated anions of the two cationic ammonium groups are acid-base homoconjugation, as catalyst. According to the present invention, the initial induction time can be reduced when the polycarbonate is manufactured and it is possible to improve the activity of the catalyst and the molecular weight of the obtained polymer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.12/817,588, filed on Jun. 17, 2010, which claims priority to KR10-2009-0054600, filed on Jun. 18, 2009, both of which are herebyincorporated by reference as if first set forth in their entiretyherein.

TECHNICAL FIELD

The present invention relates to a method of manufacturing apolycarbonate by copolymerizing epoxides with CO₂ using cobalt orchromium complexes, which are prepared from ligand having ammoniumsalts, as catalyst.

BACKGROUND ART

An aliphatic polycarbonate is a biodegradable copolymer, is a materialuseful for packages or coatings. The method for preparing apolycarbonate from epoxides and CO₂ is highly environmental-friendlyconsidering that any harmful compound phosgene is not used and that CO₂is taken with low cost.

Since 1960s, various types of catalysts have been developed to preparepolycarbonate from epoxides and CO₂. Recently, the present inventor hasdisclosed highly-active and highly-selective catalyst synthesized fromSalen[Salen:([H_(z)Salen=N,N′-bis(3,5-dialkylsalicylidene)-1,2-ethylenediamine]-typeligand including the quaternary ammonium salt [Bun-Yeoul Lee, KoreanPatent No. 10-0853358 (Registration date: Aug. 13, 2008); Bun-Yeoul Lee,Sujith S, Eun-Kyung Noh, Jae-Ki Min, Korean Patent Application No.10-2008-0015454 (Filing date: Feb. 20, 2008); Bun-Yeoul Lee, Sujith S,Eun-Kyung Noh, Jae-Ki Min, PCT/KR2008/002453 (Filing date: Apr. 30,2008); Eun Kyung Noh, Sung Jae Na, Sujith S, Sang-Wook Kim, and BunYeoul Lee*, J. Am Chem. Soc. 2007, 129, 8082-8083 (2007 Jul. 4); SujithS, Jae Ki Min, Jong Eon Seong, Sung Jea Na, and Bun Yeoul Lee, Angew.Chem. Int. Ed., 2008, 47, 7306-7309. (2008 Sep. 8)]. The catalystdisclosed by the present inventor shows high-activity andhigh-selectivity, can be used for preparing high molecular weightcopolymer, and is commercially applicable due to the polymerization athigh temperature. Furthermore, since the ligand includes the quaternaryammonium salt, it has an advantage of easy recovery and recycling thecatalyst after polymerization.

Furthermore, the present inventor has carefully analyzed the structureof the catalyst showing especially high-activity and high-selectivityamong a group of catalysts of said patent, and therefore proved that thestructure is unique, unknown before in which a nitrogen atom ofSalen-ligand is not coordinated but oxygen atoms are coordinated to ametal atom (example 1). Accordingly, the invention relating to a newtype of catalyst system obtained from the result filed as Korean PatentApplication No. 10-2008-0074435 (Filing: 2008 Jul. 30).

Example 1

The state of dinitrophenolate (DNP) was revealed by the NMR studies ofthe compound of the example 1. More specifically, two of four DNPsincluded in the compound are always coordinated to cobalt, and other twoof them are fluxional between coordinated state and decoordinated state,where the degree of coordination state can be different, according tothe change in temperature, solvents, and substituents of ligand (R, R1,R2). The following figure shows the state of DNP according to thecatalyst structure at room temperature in THF solvent, which medium isvery similar to the polymerization reaction medium. In compound 1′, thefluxional motion is too high in time-scale that the signals of thefluxional DNP are not observed in the NMR spectrum. In both complex 2′and 3′, the fluxional DNPs stay mostly in a decoordinated state but,those in 2′ stay in the decoordinated state for a longer time. That is,the order of the degree of staying in coordinated state of the twofluxional DNPs (i.e. binding affinity to cobalt) is 1′>3′>2′. Whereas,the order of activity (TOF) observed in the CO₂/propylene oxidecopolymerization is vice versa or 2′>3′>1′. This implies that theactivity is lowered if the binding affinity to the cobalt of twofluxional DNPs is high.

The reason why the compound of the above structure shows high activityis explained by the characteristic that two anionic DNP ligands aresusceptible for the fluxional movement between the coordinated anddecoordinated states. The following figure shows the growth mechanism ofthe polymer chain for the CO₂/epoxide copolymerization. In thismechanism, the attacking of the carbonate anion to the coordinatedepoxide is crucial. The fluxional characteristic of the anions enablesthe carbonate anion to attack the coordinated epoxide from back-side. Inchain-growing mechanism shown as below, a high activity is expected ifthe coordinated carbonate anion can be easily transferred to adecoordinated state.

The [water]/[catalyst] ratio of polymerization solution in theCO₂/epoxide copolymerization catalyzed using the said complexes plays animportant role in realizing the catalyst activity. Though it is tried toremove water thoroughly from epoxide and CO₂, the [water]/[catalyst]ratio is not negligible especially when [epoxide]/[catalyst] ratio ishigh such as 100,000. At this high [epoxide]/[catalyst] ratio of 100000,the residual small amount water in epoxide and CO₂ influencessignificantly on the [water]/[catalyst] ratio. The high activity (TON)is obtainable only when the polymerization is implemented under thecondition of high [epoxide]/[catalyst] ratio such as 100000. Therefore,to be the commercially valuable catalyst, the catalyst should be lesssensitive to water. In case of the catalyst having said structure, itwas observed that the induction time was highly variable according tothe degree of dryness in polymerization solution. For example, when thepolymerization reaction is performed in dry winter season, thepolymerization reaction shows induction time of about 1-2 hrs, whereasthe polymerization shows even 12 hrs when polymerization is performed inhumid and hot summer season. Once the polymerization reaction began,activity (TOF) afterwards is not varying. In ¹H NMR spectroscopyexperiment, it is observed that DNP in the complex attacks propyleneoxide. This attacking rate is significantly decreased when water isdeliberately added. The two fluxional anions are stabilized throughhydrogen bonding with water, thus nucleophilic attacking rate isdecreased.

The following table 1 shows the results of terpolymerization reactionwith CO₂ by mixing propylene oxide (PO) and cyclohexene oxide (CyO)using complex 2′ of example 1. As shown in the table 1, it was observedthat induction time was varying from 45 min to 9 hr 10 min. Furthermore,it was observed that the molecular weight decreases as induction timeincreases. This irregular and sometimes long induction time may be anobstacle to the development of commercial process using this catalyst.

Additionally, it is inevitably required for commercialization toconsistently prepare high molecular weight polymer.

TABLE 1 PO CHO—CO₂ terpolymerization results Glass Induction Moleculartransition time weight temperature Activity PO:CHO (min) (Mn) (Tg, ° C.)(TOF, h⁻¹) 8:2 45 197000 53 7200 7:3 105 180000 60 6700 6:4 160 14800063 7600 5:5 40 149000 70 7000 4:6 400 66000 73 11000 3:7 450 68000 878500 2:8 550 57000 95 7000

DISCLOSURE Technical Problem

An object of the present invention is to solve the problems thatinduction time of the above catalyst system is irregular and long, thatlow molecular weight polymer is obtained, and that the activity of thecatalyst lowers, in the manufacturing a polycarbonate by copolymerizingCO₂ with epoxide.

Technical Solution

To achieve the above object, the present invention provides a method ofmanufacturing a polycarbonate including the step of copolymerizingepoxide compound and CO₂ using cobalt(III) or chrome(III) complexes(formula 1), where the ligands contains at least 3 ammonium cations,central metal has formal −1 charge, and conjugated anions of the twocationic ammonium groups are acid-base homoconjugation, as catalyst.

[L¹L²L³L⁴M]⁻[X¹ . . . H . . . X²]⁻ _(a)Z⁻ _(b)  [Formula 1]

where, M is cobalt(III) or chrome(III);

L¹ to L⁴ are anionic X-type ligands, L¹ to L⁴ are same or differentrespectively, also is able to form bidentate, tridentate or tetradentateby linking each other, at least one of L¹ to L⁴ include quaternaryammonium salt, the number of total ammonium cation included in L¹ to L⁴is 1+a+b, and hence the complex is overall neutral;

a or b is an integer; preferably a or b is a integer of 0 to 15 but notlimited thereto, and that is satisfied in 1+a+b.

The ligand(s) among L¹ to L⁴ except the ligand including the quaternaryammonium cation, or X¹ and X² are each other independently halogen anionor HCO₃ ⁻, or aryloxy anion having carbon number 6 to 20 including ornon-including one or more of halogen atom, nitrogen atom, oxygen atom,silicon atom, sulfur atom and phosphor atom, carboxy anion having carbonnumber 1 to 20; alkoxy anion having carbon number 1 to 20; carbonateanion having carbon number 1 to 20; alkylsulfonate anion having carbonnumber 1 to 20; amide anion having carbon number 1 to 20; carboxamideanion having carbon number 1 to 20; sulfonamide anion having carbonnumber 1 to 20; or carbamate anion having carbon number 1 to 20,

Z is BF₄ ⁻, ClO₄ ⁻, NO₃ ⁻ or PF₆ ⁻.

The X-type ligand is described in detail in Gary O. Spessard and Gary L.Miessler, Organometallic Chemistry, p. 46, Prentice Hall. The X-typeligand is anionic ligand such as hydrogen, chlorine or methyl, X⁻ anionis considered to conjugate to a metal element M+ cation, and the bindingof X-type ligand affects oxidation state of metal.

The embodiment of the present invention provides a method formanufacturing a polycarbonate including a step of copolymerizing epoxidecompound with CO₂ using the catalyst represented by the followingformula 2.

where, L⁵, L⁶, X³ or X⁴ is each other independently, halogen anion orHCO₃ ⁻, or aryloxy anion having carbon number 6 to 20 including ornon-including one or more of halogen atom, nitrogen atom, oxygen atom,silicon atom, sulfur atom and phosphor atom, carboxy anion having carbonnumber 1 to 20; alkoxy anion having carbon number 1 to 20; carbonateanion having carbon number 1 to 20; alkylsulfonate anion having carbonnumber 1 to 20; amide anion having carbon number 1 to 20; carboxamideanion having carbon number 1 to 20; sulfonamide anion having carbonnumber 1 to 20; or carbamate anion having carbon number 1 to 20,

c is 1 or 0,

Z is BF₄ ⁻, ClO₄ ⁻, NO₃ ⁻ or PF₆ ⁻,

R¹² and R¹⁴ may selected from methyl, ethyl, isopropyl or hydrogen, R¹¹and R¹³ is —[CH{(CH₂)₃N⁺Bu₃}₂] or —[CMe{(CH₂)₃N⁺Bu₃}₂],

Q is diradical which binds in order to connect two nitrogen atoms, saidQ is (C6˜C30)arylene, (C1˜C20)alkylene, (C2˜C20)alkenylene,(C2˜C20)alkynylene, (C3˜C20)cycloalkylene or a combined(C3˜C20)cycloalkylene, or said arylene, alkylene, alkenylene,alkynylene, cycloalkylene or a combined cycloalkylene can be substitutedwith a substituent group selected from a halogen atom, (C1˜C7)alkyl,(C6˜C30)aryl or nitro group, or include one or more hetero atom selectedfrom oxygen, sulfur and nitrogen.

More specifically, in the formula 2, Q is trans-1,2-cyclohexylene orethylene; X is 2,4-dinitrophenolate, 4-nitrophenolate,2,4,5-trichlorophenolate, 2,4,6-trichlorophenolate, orpentafluorophenolate; Z is BF₄ ⁻.

More preferably, the present invention provides a method ofmanufacturing a polycarbonate including a step of copolymerizing epoxidewith CO₂ using a catalyst of the following formula 3.

Where, L⁷, L⁸, X⁵ or X⁶ is separately independently, halogen anion orHCO₃ ⁻, or aryloxy anion having carbon number 6 to 20 including ornon-including one or more of halogen atom, nitrogen atom, oxygen atom,silicon atom, sulfur atom and phosphor atom, carboxy anion having carbonnumber 1 to 20; alkoxy anion having carbon number 1 to 20; carbonateanion having carbon number 1 to 20; alkylsulfonate anion having carbonnumber 1 to 20; amide anion having carbon number 1 to 20; carboxamideanion having carbon number 1 to 20; sulfonamide anion having carbonnumber 1 to 20; or carbamate anion having carbon number 1 to 20,

Z is BF₄ ⁻, ClO₄ ⁻, NO₃ ⁻ or PF₆ ⁻,

R¹² and R¹⁴ may selected from methyl, ethyl, isopropyl or hydrogen, R¹¹and R¹³ is —[CH{(CH₂)₃N⁺Bu₃}₂] or —[CMe{(CH₂)₃N⁺Bu₃}₂],

Q is diradical which binds in order to two nitrogen atoms, said Q is(C6˜C30)arylene, (C1˜C20)alkylene, (C2˜C20)alkenylene,(C2˜C20)alkynylene, (C3˜C20)cycloalkylene or a combined(C3˜C20)cycloalkylene, or said arylene, alkylene, alkenylene,alkynylene, cycloalkylene or a combined cycloalkylene can be substitutedwith a substituent group selected from a halogen atom, (C1˜C7)alkyl,(C6˜C30)aryl or nitro group, or include one or more hetero atom selectedfrom oxygen, sulfur and nitrogen.

More specifically, in the formula 3, Q is trans-1,2-cyclohexylene orethylene; X is 2,4-dinitrophenolate, 4-nitrophenolate,2,4,5-trichlorophenolate, 2,4,6-trichlorophenolate, orpentafluorophenolate; Z is BF₄ ⁻.

The complex according to the present invention is manufactured by themethod of manufacturing a catalyst, including synthesizing ligand havingammonium salts, reacting a metal acetate (where metal is cobalt orchromium) with the ligand having ammonium salt, removing the generatedacetic acid to obtain cobalt(II) complexes, and oxidizing them usingoxygen as oxidizing agent in the presence of adequate acid (HX) toobtain cobalt(III) compound, and then anion exchange reaction using60˜100 mol % of NaX. The ligand having ammonium salt is manufacturedaccording to the present inventors published method (Bull. Korean Chem.Soc. 2009, 30, 745).

X in the acid (HX) is halogen anion or HCO₃ ⁻, or aryloxy anion havingcarbon number 6 to 20 including or non-including one or more of halogenatom, nitrogen atom, oxygen atom, silicon atom, sulfur atom and phosphoratom, carboxy anion having carbon number 1 to 20; alkoxy anion havingcarbon number 1 to 20; carbonate anion having carbon number 1 to 20;alkylsulfonate anion having carbon number 1 to 20; amide anion havingcarbon number 1 to 20; carboxamide anion having carbon number 1 to 20;sulfonamide anion having carbon number 1 to 20; or carbamate anionhaving carbon number 1 to 20.

The present invention provides a method of manufacturing a polycarbonateincluding a step of polymerizing epoxide compound and CO₂ using cobaltcomplex selected from the said formula 1 to 3 as catalyst.

The said epoxide compound can be selected from the group consisting of(C2˜C20)alkyleneoxide substituted or unsubstituted with halogen oralkoxy; (C4˜C20)cycloalkyleneoxide substituted or unsubstituted withhalogen or alkoxy; and (C8˜C20)styreneoxide substituted or unsubstitutedwith halogen, alkoxy, alkyl or aryl. The said alkoxy is specificallyalkyloxy, aryloxy, aralkyloxy, etc., the said aryloxy is phenoxy,biphenyloxy, naphtyloxy, etc. The said alkoxy, alkyl and aryl can be onehaving substituents selected from halogen atom or alkoxy group.

The said epoxide compound is, for example, ethylene oxide, propyleneoxide, butene oxide, pentene oxide, hexene oxide, octene oxide, deceneoxide, dodecene oxide, tetradecene oxide, hexadecane oxide, octadeceneoxide, butadiene monoxide, 1,2-epoxide-7-octene, epifluorohydrine,epichlorohydrine, epibromohydrine, isopropyl glycidyl ether, butylglycidyl ether, t-butyl glycidyl ether, 2-ethylhexyl glycidyl ether,allyl glycidyl ether, cyclopentene oxide, cyclohexene oxide, cycloocteneoxide, cyclododecene oxide, alpha-pinene oxide, 2,3-epoxidnobonene,limonene oxide, dieldrine, 2,3-epoxidepropylbenzene, styrene oxide,phenylpropylene oxide, stylbene oxide, chlorostylbene oxide,dichlorostylbene oxide, 1,2-epoxy-3-phenoxypropane, benzyloxymethyloxirane, glycidyl-methylphenyl ether, chlorophenyl-2,3-epoxidepropylether, epoxypropyl methoxyphenyl ether, biphenyl glycidyl ether,glycidyl naphtyl ether, etc.

The epoxide compound can be used for polymerization using organicsolvent as reaction medium, and the said solvent is, for example, analiphatic hydrocarbon such as pentane, octane, decane and cyclohexane,etc., an aromatic hydrocarbon such as benzene, toluene, and xylene,etc., and halogenated hydrocarbon such as chloromethane,methylenechloride, chloroform, carbontetrachloride, 1,1-dichloroethane,1,2-dichloroethane, ethylchloride, trichloroethane, 1-chloropropane,2-chloropropane, 1-chlorobutane, 2-chlorobutane,1-chloro-2-methylpropane, chlorobenzene and bromobenzene, etc., it canbe used single or combination of two or more. More preferably, bulkpolymerization using monomer itself as solvent can be performed.

Molar ratio of an epoxide compound to a catalyst, that is, an epoxidecompound: a catalyst is useful at 1,000 to 1,000,000, preferably 50,000to 200,000.

In the said copolymerization step, the pressure of CO₂ is atmosphericpressure to 100 bar, preferably 5 bar to 30 bar.

The polymerization temperature in the copolymerization is 20° C. to 120°C., preferably 50° C. to 90° C.

As the method of polymerizing polycarbonate, it can be used batchpolymerization, semibatch polymerization, or continuous polymerization.In case of batch polymerization or semibatch polymerization, thereaction time is 1 to 24 hrs, preferably 1.5 to 4 hrs. The averageretention time of the catalyst in continuous polymerization is alsopreferably 1.5 to 4 hrs.

According to the present invention, the polycarbonate thatnumber-average molecular weight (Mn) is 5,000 to 1,000,000 and molecularweight distribution (that is, Mw/Mn) is 1.05 to 4.0, can bemanufactured. In the above, Mn means number-average molecular weightmeasured on GPC using polystyrene standards. The molecular weightdistribution value (Mw/Mn) is the ratio between weight-average molecularweight (Mw) and number-average molecular weight (Mn) measured on GPC.

The obtained polycarbonate polymer comprises 80% or more carbonatelinkages, frequently 95% or more carbonate linkages. The polycarbonatemanufactured according to the present invention is easily degradable,has no residue and soot in combustion, and is a useful material as forexample, packages, insulator or coatings.

Advantageous Effects

As described above, the reason why the conventional catalyst shows highactivity is due to the fluxional characteristic of two anionic ligandsbetween coordinated and decoordinated states. Further, if the fluxionalanionic ligands could easily decoordinated from metal center, that is,when less interacts with metal center, the activity increases. Thepresent invention relates to increasing the activity by weakening theinteraction of anion with metal center, by substituting the fluxionalanionic ligand with acid-base homoconjugation, for example [DNP . . . H. . . DNP]⁻ (refer to table 2 and table 3). If the activity of thecatalyst increases, generally the molecular weight′ increases (refer totable 2 and table 3). Further, the sensitivity to the water can bereduced by substituting two anions with acid-base homoconjugation (referto table 2 and table 3). As described above, in the case of the existingcatalyst, the induction time varies largely according to the level ofdryness in polymerization solution; it was explained as the fluxionalanion forms hydrogen-bonds with water which reduces the nucleophilicattack of the anion onto propylene oxide. In the case of acid-basehomoconjugation, hydrogen bonds exist already in it and the sensitivityto water is relaxed, consequently the variation of induction time beingrelatively less.

If DNP forms hydrogen bonding with water, its nucleophilicity islowered, thereby the reaction rate with PO is lowered, however, in thecase of the homoconjugation, it forms hydrogen-bonding in itself, butthe nucleophilic attacking rate to PO improves on the contrary. FIG. 1is ¹H NMR spectrum, showing the reaction between compound 6 of thefollowing formula and propylene oxide. It could be observed that thehomoconjugation reacts with propylene oxide, the anion of Meisenheimersalt (the signal marked with *) and alcohol compound2,4-(NO₂)₂C₆H₃—OCH₂CH(Me) OH and 2,4-(NO₂)₂C₆H₃—OCH(Me) CH₂OH (thesignal marked with x) was formed, the coordinated DNP (the signal markedwith ̂) is exist as it is. When the activity of the compound 3 and 6 andwith propylene oxide is counted by numbering the reacted propylene oxidefor early 30 minutes, it could be seen the compound 6 is twice as fastas, and these results are same as the results that the activity ofcompound 6 is higher than that of compound 3. Also, in case of compound4, the activity with propylene oxide is largely lowered by adding 50equivalent of water, however as seen in FIG. 1, the activity of thecompound 6 with propylene oxide in the presence of 50 equivalent ofwater is not lowered. This result explains the reason why thesensitivity of compound 6 to water is less than that of the compound 3.

The strength of hydrogen bonds in acid-base homoconjugation is muchhigher than the general strength of hydrogen bonds. In the reference inShan, S.-o. and Loh, S. and Herschlag, D, Science 1996, 272, 97, it isreported that in the case of forming hydrogen bonds between the acid andbase of which PK_(a) value is same, the strength of hydrogen bonds isunusually bigger, thereby the activity of enzyme is maximized. Further,in the x-ray single crystal structure of (18-Crown-6-k⁶O) potassium2,4-dinitrophenolate 2,4-dinitrophenol homoconjugation that is reportedby Barnes, J. C. and Weakley, T. J. R., Acta Cryst. 2003, E59, m160, thelength of oxygen-oxygen bonds connected by hydrogen bonds is 2.453(4) Å.This bond length supports the very strong hydrogen bonds. (Paola Gilli,P.; Bertolasi, V.; Ferretti, V.; and Gilli, V. J. Am. Chem. Sec. 1994,116, 909:). Also, in the reference Magonski, J. and Pawlak, Z andJasinski, T, J. Chem. Soc. Faraday Trans. 1993, 89, 119, the equilibriumconstant to homoconjugation forming is about 100, and two components inorganic solvent exist as homoconjugation as suggested by formula 4. Inpractice, in the ¹H NMR spectrum of compound 6 that are measured inthf-d₈ solvent, the coordinated DNP signal marked with * and thehomoconjugation [DNP . . . H . . . DNP]⁻ signal marked with ̂ could beseen clearly.

DESCRIPTION OF DRAWINGS

FIG. 1 is ¹H NMR spectrum in dmso-d₆ showing the reaction betweencompound 4 and propylene oxide. The signal marked with * is anion ofMeisenheimer salt which produced by DNP anion's reaction, the signalmarked with x is 2,4-(NO₂)₂C₆H₃—OCH₂CH(Me)OH and2,4-(NO₂)₂C₆H₃—OCH(Me)CH₂OH, the signal marked with ̂ is DNP.

FIG. 2 is ¹H NMR spectrum of compound 4 that measured in thf-d8 solvent.The signal marked with * is a coordinated DNP signal, the signal markedwith ̂ is a homoconjugation signal.

BEST MODE

Hereinafter, the present invention will be described in more detail withreference to the following Examples, but the scope of the presentinvention is not limited thereto.

Preparing Example 1 Synthesis of 60 Mol % Sodium Dinitrophenolate(NaDNP)

A commercially available dinitrophenol (10.0 g, 54.3 mmol) was dissolvedin 250 mL of methylenechloride, and water was removed on anhydrousmagnesium sulfate. Solvent was removed by filtration under the reducedpressure. After the anhydrous dinitrophenol (10.0 g, 54.3 mmol) wasdissolved in anhydrous THF (300 mL), NaH (0.782 g, 32.6 mmol) was addedslowly. After all NaH was added, the solution was stirred for 3 hrs.Solvent was removed under reduced pressure to obtain 60 mol % sodiumdinitrophenolate.

Preparing Example 2 Synthesis of 100 Mol % Sodium Dinitrophenolate

The anhydrous dinitrophenol (10.0 g, 54.3 mmol) was dissolved inanhydrous THF (300 mL) and then NaH (1.30 g, 54.3 mmol) was addedslowly. After the solution was stirred for 3 hrs, solvent was removedunder the reduced pressure to obtain 100 mol % sodium dinitrophenolate.

Example

Example 1 Synthesis of Compound 4

The ligand was synthesized according to the published reference (Bull.Korean Chem. Soc. 2009, 30, 745). In the glove box, after ligand (0.376g, 0.230 mmol) and Co(OAc)₂ (0.041 g, 0.230 mmol) was quantitativelyadded in 50 mL round flask, ethanol (17 mL) was added and the resultingsolution was stirred for 3 hrs. Diethyl ether (20 ml) was added toprecipitate a solid which was filtered using a glass filter, and thenwashed with diethyl ether (10 mL) three times. The solvent in theobtained orange solid was completely removed under the reduced pressure.2,4-Dinitrophenol (0.022 g, 0.117 mmol) was added to a flask containingthe above prepared Co(II) compound (0.200 g, 0.117 mmol), and themethylene chloride (5 mL) was added. After the solution was stirred for3 hrs under oxygen atmosphere, the above prepared 60 mol % sodiumdinitrophenolate (0.121 g, 0.585 mmol) was added and agitated for 12hrs. After the solution was filtered using a glass filter, solvent wasremoved under the reduced pressure to obtain a reddish brown solid(0.284 g, 0.111 mmol). Yields 95%. ¹H NMR (dmso-d₆, 4012): δ 8.62 (br,3H, (NO₂)₂C₆H₃O), 8.03 (br, 3H, (NO₂)₂C₆H₃O), 7.87 (br, 1H, CH═N),7.41-7.22 (br, 2H, m-H), 6.71 (br, 3H, (NO₂)₂C₆H₃O), 3.62 (br, 1H,cyclohexyl-CH), 3.08 (br, 16H, NCH₂), 2.62 (s, 3H, CH₃), 2.09 (1H,cyclohexyl-CH), 1.89 (1H, cyclohexyl-CH), 1.72-1.09 (br, 37H), 0.87 (br,18H, CH₃) ppm.

Example 2 Synthesis of Compound 5

The compound 5 was synthesized by the same method as compound 4 using4-nitrophenol. The reaction rate of 02-oxidation was slow, so thereaction was performed for 3 days. The anion exchange reaction wasperformed using 60 mol % sodium 4-hitrophenolate which are manufacturedaccording to the method of manufacturing above 60 mol % sodium2,4-dinitrophenolate. Yields 95%. ¹H NMR (dmso-d₆, 40° C.): δ 7.96 (br,4H, (NO₂)C₆H₄O), 7.77 (br, 1H, CH═N), 7.49 (br, 1H, (NO₂)C₆H₄O), 7.10(br, 1H, m-H), 7.02 (br, 2H, m-H, (NO₂)C₆H₄O), 6.56 (br, 4H,(NO₂)C₆H₄O), 3.97 (br, 1H, cyclohexyl-CH), 2.96 (br, 16H, NCH₂) 2.61 (s,3H, CH₃), 2.09 (1H, cyclohexyl-CH), 1.89 (1H, cyclohexyl-CH), 1.55-1.05(br, 37H), 0.87 (br, 18H, CH₃) ppm.

Example 3 Synthesis of Compound 0.6

The compound was synthesized by the same method as compound 4 using2,4,5-trichlorophenol. The reaction rate of 02-oxidation was slow, sothe reaction was performed for 3 days. The anion exchange reaction wasperformed using 60 mol % sodium 2,4,5-trichlorophenolate which aremanufactured according to the method of manufacturing above 60 mol %sodium 2,4,5-trichlorophenolate. Yields 95%. ¹H NMR (dmso-d₆, 40° C.): δ8.34 (s, 1H, C₆H₂Cl₃O), 7.70 (s, 1H, CH═N), 7.39 (s, 2H, C₆H₂Cl₃O), 7.09(s, 1H, m-H), 6.97 (s, 1H, m-H), 6.85 (s, 2H, C₆H₂Cl₃O), 6.69 (s, 1H,C₆H₂Cl₃O), 4.13 (br, 1H, cyclohexyl-CH), 2.99 (br, 16H, NCH₂), 2.63 (s,3H, CH₃), 2.10 (br, 1H, cyclohexyl-CH₂), 1.84 (br, 1H, cyclohexyl-CH₂),1.57-1.05 (br, 37H), 0.84 (br, 18H, CH₃) ppm.

Example 4 Synthesis of Compound 7

The compound 7 was synthesized by the same method as compound 4 using2,4,6-trichlorophenol. The reaction rate of O₂-oxidation was slow, sothe reaction was performed for 3 days. The anion exchange reaction wasperformed using 60 mol % sodium 2,4,6-trichlorophenolate which aremanufactured according to the method of manufacturing above 60 mol %sodium 2,4,6-trichlorophenolate. Yields 98%. ¹H NMR (dmso-d₆, 40° C.): δ7.92 (br, 1H, CH═N), 7.44 (br, 1H, m-H), 7.31 (br, 1H, m-H), 7.20 (br,6H, C₆H₃Cl₃O), 3.60 (br, 1H, cyclohexyl-CH), 3.10 (br, 16H, NCH₂), 2.65(s, 3H, CH₃), 2.01 (br, 1H, cyclohexyl-CH₂), 1.83 (br, 1H,cyclohexyl-CH₂), 1.66-1.15 (br, 37H), 0.88 (br, 18H, CH₃) ppm.

Example 5 Synthesis of Compound 8

The compound 8 was synthesized by the same method as compound 4 usingpentafluorophenol. The reaction rate of O₂-oxidation was slow, so thereaction was performed for 3 days. The anion exchange reaction wasperformed using 60 mol % sodium pentafluorophenol which are manufacturedaccording to the method of manufacturing above 60 mol % sodiumpentafluorophenol. Yields 97%. ¹H NMR (dmso-d₆, 40° C.): δ 7.85 (br, 1H,CH═N), 7.18 (br, 1H, m-H), 7.10 (br, 1H, m-H), 4.03 (br, 1H,cyclohexyl-CH), 3.09 (br, 16H, NCH₂), 2.46 (br, 3H, CH₃), 2.09 (br, 1H,cyclohexyl-CH₂), 1.87 (br, 1H, cyclohexyl-CH₂), 1.70-1.15 (br, 37H),0.88 (br, 18H, CH₃) ppm.

Example 6-10 CO₂/Propylene Oxide Copolymerization

After the compound 4-8 that was manufactured in above example 1-5(0.0027 mmol, monomer/catalyst=50,000) and propyleneoxide (7.71 g, 135mmol) were added 50 mL bomb reactor, the reactor was assembled. Thereactor was immersed in the oil bath of which temperature was controlledto 80° C., and then was stirred for about 15 minutes to make thesolution temperature reach the bath temperature. The CO₂ gas was chargedat 20 bar pressure. It could be observed that the CO₂ pressure wasdropped by the progress of the polymerization. The reaction wasterminated by removing CO₂ gas at pressure drop of 7 bar (30 minreaction). The 10 g of monomer was further added in the obtained viscoussolution to reduce the viscosity, and then the solution was passedthrough the silica gel (400 mg, Merck, 0.040-0.063 mm size (230-400mesh)) pad to obtain colorless solution. The white solid of polymer wasobtained by removing the monomer under the reduced pressure. TON(Turnover Number) and TOF (Turnover Frequency) were calculated bymeasuring the weight, the molecular weight of above obtained polymer wasmeasured using GPC. The selectivity to polymer formation versuspropylene carbonate was calculated by analyzing the 1H NMR spectrum. Thefollowing table 2 shows the polymerization results.

TABLE 2 The polymerization result of CO₂/propylene oxide of Example 6-10

Molecular Molecular weight weight Induction TOF Selectivity (Mn)distribution Example Catalyst time (min) (h-1) (%) ×10⁻³ (Mw/Mn)  6^(a)4 60 15000 99 270 1.26 7 5 0 13000 95 240 1.36 8 6 0 16000 94 190 1.43 97 60 7400 85 90 1.32 10  8 60 12000 94 170 1.35 ^(a)monomer/catalyst =100,000

Comparative Example

Comparative Example 1 Synthesis of Compound 3

After Co (III) compound was formed by the method as the manufacturingmethod of compound 4, the anion exchange reaction was performed by usingthe above obtained. 100 mol % sodium dinitrophenolate (5 equivalent).Yields 94%. ¹H NMR (dmso-d₆, 40° C.): δ 8.59 (br, 2H, (NO₂)₂C₆H₃O), 7.89(br, 1H, CH═N), 7.79 (br, 2H, (NO₂)₂C₆H₃O), 7.41-7.18 (br, 2H, m-H),6.32 (br, 2H, (NO₂)₂C₆H₃O), 3.62 (br, 1H, cyclohexyl-CH), 3.08 (br, 16H,NCH₂). 2.62 (s, 3H, CH₃), 2.08 (1H, cyclohexyl-CH), 1.82 (1H,cyclohexyl-CH), 1.69-1.05 (br, 37H), 0.83 (br, 18H, CH₃) ppm.

Comparative Example 2 Synthesis of Compound 9

After Co (III) compound was formed by the method as the manufacturingmethod of compound. 5, the anion exchange reaction was performed byusing the above obtained 100 mol % sodium 4-nitrophenolate (5equivalent). Yield 98%. ¹H NMR (dmso-d₆, 40° C.): δ 7.75 (br, 2H,C₆H₄NO₂O), 7.66 (br, 1H, CH═N), 7.37 (br, 2H. C₆H₄NO₂O), 6.98 (br, 1H,m-H), 6.91 (br, 3H, m-H, C₆H₄NO₂P), 6.21 (br, 2H, C₆H₄NO₂O), 3.85 (br,1H, cyclohexyl-CH), 2.86 (br, 16H, NCH₂), 2.50 (s, 3H, CH₃), 1.98 (br,1H, cyclohexyl-CH₂), 1.78 (br, 1H, cyclohexyl-CH₂), 1.56-0.90 (br, 37H),0.72 (br, 18H, CH₃) ppm.

Comparative Example 3 Synthesis of Compound 10

After Co (III) compound was formed by the method as the manufacturingmethod of compound 6, the anion exchange reaction was performed by usingthe above obtained 100 mol % sodium 2,4,5-trichlorophenolate (5equivalent). Yield, 94%. ¹H NMR (dmso-d₆, 40° C.): δ 8.34 (s, 1H,C₆H₂Cl₃O), 7.70 (s, 1H, CH═N), 7.11 (s, 1.5H, C₆H₂Cl₃O), 7.09 (s, 1H,m-H), 6.97 (s, 1H, m-H), 6.69 (s, 1H, C₆H₂Cl₃O), 6.39 (s, 1.5H,C₆H₂Cl₃O), 4.13 (br, 1H, cyclohexyl-CH₂), 1.84 (br, 1H, cyclohexyl-CH₂),1.57-1.05 (br, 37H), 0.84 (br, 18H, CH₃) ppm.

Comparative Example 4 Synthesis of Compound 11

After Co (III) compound was formed by the method as the manufacturingmethod of compound 6, the anion exchange reaction was performed by usingthe above obtained 100 mol % sodium 2,4,6-trichlorophenolate (5equivalent). Yield, 99%. 41 NMR (dmso-d₆, 40° C.): δ 7.99 (br, 1H,CH═N), 7.46 (br, 1H, m-H), 7.31 (br, 1H, m-H), 6.91 (br, 5H, C₆H₂Cl₃O),3.55 (br, 1H, cyclohexyl-CH₂), 3.08 (br, 16H, NCH₂), 2.62 (s, 3H, CH₃),2.00 (br, 1H, cyclohexyl-CH₂), 1.80 (br, 1H, cyclohexyl-CH₂), 1.70-1.15(br, 37H), 0.87 (br, 18H, CH₃) ppm.

Comparative Example 5 Synthesis of Compound 12

After Co(III) compound was formed by the method as the manufacturingmethod of compound 6, the anion exchange reaction was performed by usingthe above obtained 100 mol % sodium pentafluorophenolate (5 equivalent).Yield, 97%. ¹H NMR (dmso-d₆, 40° C.): δ 7.85 (br, 1H, CH═N), 7.18 (br,1H, m-H), 7.10 (br, 1H, m-H), 4.03 (br, 1H, cyclohexyl-CH), 3.09 (br,16H, NCH₂), 2.46 (br, 3H, CH₃), 2.07 (br, 1H, cyclohexyl-CH₂), 1.89 (br,1H, cyclohexyl-CH₂), 1.70-1.15 (br, 37H), 0.88 (br, 18H, CH₃) ppm.

Comparative Example 6-10 CO₂/Propylene Oxide Copolymerization

The polymerizations were performed by using the catalyst of formula 5.The following table 3 shows the polymerization results.

TABLE 3 CO₂/propylene oxide copolymerization results of comparativeexample 6-10 Induc- Molecular tion Selec- Molecular weight Exam- Cata-time TOF tivity weight distribution ple lyst (min) (h⁻¹) (%) (Mn) ×10⁻³(Mw/Mn)  6^(a) 3 240^(b)   10000 99 140 1.17 7 9 0 7900 93 170 1.31 8 100 10000 94 170 1.37 9 11 0 0 10  12 240  8400 94 140 1.30^(a)monomer/catalyst = 100,000; ^(b)the induction time is notconsistent, the value of 60~600 minutes was observed.

1. A method of manufacturing a complex of following formula 1 (said L¹,L², and X are same as those of following formula 1), comprising: a stepof reacting a ligand of L¹ or L² with metal acetate (the metal is cobaltor chromium) to bind the metal with ligand; and a step of adding theacid (HX) in the presence of oxygen after binding said metal withligand, and oxidizing the metal to coordinate anion X to the metal; anda step of ion exchanging by using the metal salt (the metal is lithium,sodium, potassium) having anion X:[L¹L²L³L⁴M]⁻[X¹ . . . H . . . X²]⁻ _(a)Z⁻ _(b)  [formula 1] where, M iscobalt(III) or chromium(III); L¹ to L⁴ are anionic X-type ligands, L¹ toL⁴ are same or, different respectively, also is able to form bidentate,tridentate or tetradentate by linking each other, at least one of L¹ toL⁴ include quaternary ammonium salt, the number of total ammonium cationincluded in L¹ to L⁴ is 1+a+b, and hence the complex is overall neutral;a or b is an integer; the ligand(s) among L¹ to L⁴ except the ligandincluding the quaternary ammonium cation, or X¹ and X² are each: otherindependently halogen anion or HCO₃ ⁻, or aryloxy anion having carbonnumber 6 to 20 including or non-including one or more of halogen atom,nitrogen atom, oxygen atom, silicon atom, sulfur atom and phosphor atom,carboxy anion having carbon number 1 to 20; alkoxy anion having carbonnumber 1 to 20; carbonate anion having carbon number 1 to 20;alkylsulfonate anion having carbon number 1 to 20; amide anion havingcarbon number 1 to 20; carboxamide anion having carbon number 1 to 20;sulfonamide anion having carbon number 1 to 20; or carbamate anionhaving carbon number 1 to 20, Z is BF₄ ⁻, ClO₄ ⁻, NO₃ ⁻ or PF₆ ⁻.